Charles a



(No Model.)

C. A. LIEB. ELASTIC METALLIC POLE FOR ELECTRIC WIRES.

Patented Mar. 31,1891.

:ATENT Fries.

CHARLES A. LIFE, OF NEXV YORK, N. Y.

ELASTIC METALLIC POLE FOR ELECTRIC WIRES.

SPECIFICATION forming part of Letters Patent No. 449,125, dated March 31, 1891. Application filed November 3, 1890- Serial No. 370,158. (No model.)

T0 aZZ whom it may concern,

Be it known that 1, CHARLES A. LIEB, a citizen of the United States, and a resident of New York, in the county of New York and State of New York, have invented a certain new and useful Elastic Metallic Pole for Electric Wires, of which the following is a specification.

My invention relates to improvements in poles for supporting the wires of telegraph, telephone, and similar lines, also for overhead electric-railway systems and other analogous uses, it being applicable also to poles used for other purposes; and it consists in constructing the pole in such manner that elasticity is given to it by reason of the fact that the parts of the pole are capable of movement relative to each other, whereby elasticity is secured and gradually-increasing resistance to the strain is presented.

In the drawings, Figure 1 illustrates a form of my invention in which the metal is disposed spirally and taperingly. Fig. 2 illustrates a form in which the metal is folded in a tapering manner upon itself, so as to form a tapering tube, the meeting edges being det-ached and furnished with re-enforces. Fig. 3 illustrates a pole made of fiat metal disposed as springs. Fig. 4 illustrates a pole in which the detached edges overlap each other. Fig. 5 illustrates a pole in which the detached meeting edges overlap and one of them is reenforced. Fig. 6 illustrates a method of implanting a pole in the ground. Fig. 7 illustrates a cross-section on the linerrsc of Fig. 2. Fig. 8 illustrates a cross-section on the line y y of Fig. at. Fig. 9 illustrates a cross-section on the line .2 z of Fig. 5.

The characteristic feature of my present invention is, as before suggested, that the poles are flexible or elastic, and that in them all, as pressure is applied, the resistance of the pole gradually increase-s; also, they are so constructed that buckling of the pole, whereby they are ruined, is practically impossible. The desire for such a pole has been long felt by those who are practically familiar with this art for a number of reasons.

First. Because broken or buckled poles are of frequent occurrence, especially on overhead electric-railway systems, because the spanwires have at all times to be tense in order properly to sustain the trolley-wires and other attachments, the span of which, being frequently Very long, imposes'a severe strain upon the poles, and if the span-wires are set up taut during warm weather, then when cold weather comes on the span-wires and also the trolley-wires contracting very greatly increase this strain, especially on curves. This alone frequently breaks or buckles poles or causes fracture of the wires, and if, in addition to this strain, snow and ice accumulate upon them, this added weight almost invariably occasions fracture either of the poles or of the wires or their fixtures.

Second. It frequently happens that a spanwire which has been stretched taut by reason of its ordinary tension plus, perhaps, contraction during cold weather, and has thus put the poles under strain about to the limit of their resistance, is struck a blow from a trolley which has left the trolley-wire, thus occasioning buckling of the pole or fracture of the span-wire or some of its attachments.

Third. If the pole be elastic, then the spanwires and the trolley-wires as well will be at all times under an equal tension, or substantially so, because the poles will then take up any slack which may occur, thus automatically adjusting the wires to their work.

In Fig. l I show a form of my invention in which the pole is made by a spirally and taperingly wound strip or ribbon of metal given the shape illustrated, preferably by winding it upon a tapering arbor. The meeting edges of the metal which may overlap, if desired, are not fastened to each other, at least not at all points, so that when the strain comes upon the pole and the pole is deflected from the vertical line slight openings will occur upon the convex side of the pole between the adjoining edges of the strip, and on the other hand these edges will abut against each other on the concave side of the pole. This will occasion a jam, necessitating not only a horizontal but also a vertical and, as .it were, edgewise bonding or springing of the metal. Thus it will be seen that, although the pole will bend somewhat easily at first to a certain degree, nevertheless, thereafter it gradually becomes stronger and stronger, so that it will obey the demand of the wires to a certain extenti. 6., sufficient to keep them always tense and in proper working condition; but if anything should occur which would tend to draw the poles over or break them, then they become controlling, and the wires must break and not the poles. This is of course greatly to be preferred of the two, because much more easily and cheaply repaired.

In Fig. 2 Ishow a form which embodies the same principles as shown and described of the structure in Fig. 1. In it. the metal is bent or folded upon itself in the form of a tapering cylinder, the meeting edges whereof, as seen in Fig. 7, are provided with two longitudinally-run flanges c c, which preferably project inwardly toward the center of the pole. The pole is designed to be set in such manner that the strain will tend to bend the pole over toward these flanges c 0, so that it would buckle if it could through these flanges; but it will be observed that as the strain is applied to the pole these flanges c c, which are not united together, but, on the contrary, slightly separated, will approach each other and finally abut against each other, and when this takes place the pole will become a rigid one, substantially; but prior to their abutting together the pole will be quite flexible. On the top of the pole shown in Fig. 2 I show a chamber made by enlarging the metal sutliciently to take out the two flanges c c and put them into the chamber. This chamber is to receive the switches, lightningarrester, and other appurtei'iances of these structures. This has, however, been fully set forth and claimed in another application filed byme of even date herewith. Therefore I do not claim it here. The metal may be swaged up while hot into such shape as necessary for this chamber (Z.

In Fig. 3 I show another form of pole which has the same essential features of both method and operation as the poles in Figs. 1 and 2. It is made of a series of leaves marked a, f, g, h, '2', andj. Theyare made of steel preferably, and may be galvanized or otherwise protected from the weather, and are so disposed relatively to each other that the strain which is applied to the outermost leaf e by the span-wire m, it being attachedthereto at Z, will cause flexure first of the leaf 6. Further strain brings into action the leaf f, next the leaf g, and so on. Thus as in the other two cases movement of the parts composing the pole relative to each other affords elas ticity, and in this case the leaves e, f, and g may be made of such tension as to simply give the automatic adjustment to the wires before referred to; but if continued suflr ciently tolninginto action the leaves 7:, 2', and J one or more of tliem,then the pole will control the wire and not the wire the pole, so that there shall be no fracture of the pole, and yet preservation of automatic adjustment of the line-wires at ordinary times. 70 7.1, &c., represent ears or clips, which preserve the upper ends of the several leaves in proper alignment with each other. This form of pole, as

also the others, if desired, may be set in a cast-metal basen, set in the ground to secure proper support; or the pole itself may be set in the ground, the lower ends of the leaves being properly bolted together in the usual way, there being preferably a stone (see Fig. 6) placed at the base of the pole, upon which itrests for a firm foundation. This, of course, is not essential. It a stone be not used, it is desirable that the lower ends of the hollow poles should be closed by a wooden plug, plank, or a metal cap of any preferred form, so that the poles will not so readily settlc or move downwardly under the pressure, as might be the case were the end left open.

In Figs. 4, 6, and S I show a construction somewhat similar to that shown in Figs. 2 and 7, Fig. 7 being a cross-section of Fig. 2 on the line out, as before stated. In said Figsnl and S the metal is rolled into a tapering cylindrical form, the edges 7!. 7L whereof, overlapping each other and in use, are slightly separated. It will be seen in this case, also, when strain is applied, the overlapping edges being upon the convex side of the pole, that these overlapping edges will approach each other, during which movement the pole will have considerable elasticity, thus alfording the automatic adjustment above referred to; but that when they meet one another the pole will be very greatly stiffened, so that it be comes practically rigid or at least much stiffer, and it then controls the wire, whereas previously the wires controlled it, thus securing the advantages shown to exist in the other forms.

In Figs. and 9, the latter being a crosssection of the former on the line .2, I show still another construction, in which the same qualities, features, and advantages obtain as in the other forms. It is, in effect, a combination of the form shown in cross-section in Figs. 7 and S-that is to say, the two edges 7L h overlap each other, as in Fig. 8, and one of the edges has the flange 0 turned inward, as shown in Fig. 0. The operation of this form, in view of what has already been said, does not require further explanation.

A very important feature which I have not heretofore adverted to is this, that each of these poles has a re-enforce at the side, upon which buckling in the old forms of pole occurs, whereby it is praeticallyimpossible for buckling to happen with my new construction. In Fig.1 this re-cnforce consists in the abutting togetherof themeeting edges of the spirally'disposed metal. In Fig. 2 it is the two flanges c c, which are placed edgewise to the strain. In Fig. 3 it is the gradual thick ening of the pole in the direction of the strain. In Fig. fl: it is a double thickness of metal, each thickness sustaining the other at the part where the buckling must occur, and in Fig. 5 it is a combination of the double thickness of metal and the edgewise presentation of a flange to the strain.

I do not limit myself to the details of construction shown and described, since those who are familiar with this art will perceive that other forms may be employed which practically embody my invention.

Having described my invention, I claim 1. A pole having more than one thickness of metal extending longitudinally along its concave side when under strain, substantially as set forth.

2. A pole re-enforced against buckling on its concave side when under strain, substantially as set forth.

3. A metallic pole constructed and arranged to have two or more opposing faces or surfaces adapted to movement relative to each other, which, When in contact, stiffen the pole, substantially as set forth,

4. A metallic pole composed of a strip of CHARLES A. LlEB.

Witnesses:

PHILLIPs ABBOTT, WILLIAM OLSEN. 

